Frederick bernard d



atten tartes @anni @frn FREDERICK BERNARD DGIIRING, OF LONDON, ENGLANDLetters Patent No. 72,465, dater-Z .December 24, 1867; patentedirtEngZancZ, September 4, 1867.

' IMPROVED MACHINE POIt BORING ROCKS.

T ALL WHOM IT MAY CONCERN:

Be it known that I, FREDERICK BERNARD D ERING, of London, England, civilengineer, have invented or discovered certain Improvements 4in Enginesor Machinery for Boring or Working in Rock or other Mineral; and I dohereby declare that the following is a full, true, and exact descriptionthereof, reference beinghad to the annexed drawings; that is to say'- YMy invention mainly consists in employing the main cylinder of theengine as a distributor of the compressed air or other motive-Enid tothe valve-cylinder, and other small cylinders used in connectiontherewith, the motive-Huid not having been previously utilized in themain cylinder.

Figures 1 and 1 are longitudinal sections, showing the piston at the twoends of' its stroke.

Figure 2, a section through XX, fig; l.

Figures 3 and 4 are top and bottom plans, and

Figure 5 a rear elevation of an engine constructed according to theprinciples of myinvention.v

The main cylinder, A, in addition to its'ordinary'ports for admittingthe i'luid for producing the forward and back strokes ofthe piston, hastwoports,fd,"mcommunication, respectively, throughA pipesfd, with th'eback ofthe valve of the cylinder, and with the back ofa cylinder, P, fthe advance movement. The main cylinder has also a central mainsupply-port, l, in constant communication with the fluid-supply. Thepistonrod carries three pistons, a b e, forming between them twochambers. The forward chamber communicates with the outer air by apassage, e: 'The hindmost chamber always carries compressedir.

A constant pressure is maintained against the forward end of the valve,the rod of which carries four pistons, the two outer pistons forming thevalve-piston proper, while the others are piston-valves, and close andopen at th'e proper times the ports leading tothe main piston. Theforward valve-piston is of smaller area than its back piston. A'constantpressure is likewise maintained at the front of the advance-movementcylinder P, fluid communicating this pressure being supplied throughpipe 7c 7c. As the main piston is making its forward stroke, the portfisput into communication through the back chamberof the main piston withthe main supply-port Z. The fluid thus Hows to the back of thevalve-cylinder, where, acting upon a greater area than is acted upon bythe constant pressure at the front, it moves the valve forward'. Thisputs the main supply .L in communication with the front of the maincylinder, through the 'port and side pipe It, so that the main piston iscaused to make its back stroke. In the stroke it cuts off the portf. Thechamber at the back of the valve-cylinder then exhausts through thepipef, portf, and the passage e, so that the constant pressure on thefront piston of the valve-rod, not being resisted, moves the valve backto open the port leading to the back of the main piston, and so on. Inboth strokes the main exhaust is through the valvecasing at z'. Thepiston of the advance cylinder P is kept at the front by pressureexertedat the back, which is of larger area than thc front. In theforward stroke o f the main piston, the port dis passed by'the mainpiston only when the tool has cut to a determined depth, and the pistonof the advance cylinder is therefore kept at the front until the mainpiston is able `to make its full stroke, when exhaust takes placethrough the pipe d', the port ci, and the main cylinder, and itsexhaust-passages. The constant pressure on the front of the piston thendrives the piston back and withdraws the pawl carried bythe piston fromits ratchet-wheel, ready to rotate this wheel a'nd advance the engine atthe next stroke of the main piston. In some cases I reverse the valveofthe engine.

before explained; that iste say, I place the small piston at the backinstead of at the frcnt ofthe valve. The main exhaust at z' then takesthe p'lace of the main supply at L, and vice versa. A hole in the backcover of the valve may then be used to regulate the speed of the valve,an excess of constant pressure .in the forward direction being betweenthe back pistou and the one next to it. The port j', incommunicationwith the advance cylinder, instcad'of being placed so thatit is behind the piston after the completion of'a full stroke, may beplaced so that it is behind the middle partition of the piston. Theadvance piston is in this ease moved by pressure at the end of. theforward stroke. Y

A modification of the arrangement before described, and in'which alsothe main cylinder acts as a disA tributor of the motive-fluid withoutpreviously utilizing'it, consists in' fitting the main piston-rcd withfou-r pisa tons, forming between them three chambers. In this lcase itis not necessary to maintain a constant pressure against one side of thevalve-piston or against one side of the smallpiston or pistons. Thecentre chamber forms the distributor, and the two outer chambers formthe exhaust-chamber s for the other` cylinders. The foremost chambercommunicates with the outer air through the piston-rod, as in the firstarrangement, while the hindmost chamber communicates with the-foremostchamber, and thereforewith the outer air, by a pipe or passage carriedthrough the two middle pistons. The main cylinder, in this case, has, inaddition to the ordinaryperts, four ports, viz, the first incommunication with the back ofthe advance cylinder, and with the frontof the valve-cylinder, the second for admitting the fluid between thetwo middle pistons, the third in communication with the back of thevalve-cylinder, and the fourth in communication with the front of theadvance cylinder. I do not, however,

limit myself to any number oi' ports, because their number and partitionwill vary according to the number and required movements of thecylinders to be actuated therefrom, my invention consisting essentiallyin actuating thc pistons of any cylinder used in connection with themain cylinder by employing the main cylinder itself as a distributor ofthe motive-Huid to the other cylinders, such motive-duid not beingpreviously utilized in thc main cylinder.

I effect the required rotary motionot` the piston and tool by means of atwisted, square, or cornered bur, 7c, or of a rod with a spiral featheror grocverin combination with other parts, as follows: The back part oftlie piston-rod is hollow, to receive the twisted ro d,`the rear end ofwhich passes through the rear of the cylinder, and carries aratchet-wheel, m. The twisted rod is a fixture, longitudinally, but isfree to turn on its axis in one direction, while a pawl, n, whichtal-:es into the ratchet-wheel, prevents it turning in the otherdirection. In the back stroke of the piston the twisted rod is held bythe pawl, and the piston-rod, which is formed internally to it the bar,follows the twist, and is caused to rotate. In the forward stroke, thetwisted rod being free to rotate, and being more easily rotated than thepiston, the latter makes its stroke without rotating,

while the twisted rod moves round the pawl, riding over theratchet-tooth, or the piston may made to rotate in the forward, and thebar in the back stroke, the alteration being effected by reversingtbetwist.

What I claim as my invention, and desire to secure by Letters Patent, is1.l Constructing engines or machinery for boring or working in rock orother mineral in which the pistons of the small cylinders are. operatedby motive-Huid, distributed by the niain cylinder, without having beenpreviously utilized in the main cylinder, as herein described. v

2. Constructing engines or machinery for boring or working in rocks orotherv mineral in which the main cylinder itself distributes themotive-fluid at distinct portions of the stroke to other cylinders, asin the arrangements herein described.

3. Constructing engines or machinery for boring or working in rockorother mineral in which the piston ot' the main cylinder, with thetool, has the required rotary motion imparted to it by a twisted bar, orequivn alent, in combination kwith other parts, as herein described.

In witness whereof', I, the said FREDERICK BERNARD Demme, have hereuntoset my hand, this tenthV day of October, one thousand eight hundred andsixty-seven.

. F. B. DRlNG.

' Witnesses:

J. C. MEWBURN, 166 Fleet Street, London, H. GARDNER, 166 Fleet Street,London.

